JP2007157580A - Light-emitting structural body and light-emitting element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting material which improves a luminance by taking a light outside efficiently. <P>SOLUTION: A light-emitting layer is composed of a columnar portion 11 of a columnar structure like a cylindrical shape and a light-emitting portion 12 of a pyramid body like a conical shape. Efficiency for extracting light outside is improved by extracting light generated in the light-emitting portion 12 outside through the columnar portion 11. Desirably, a diameter of a conical bottom of the light-emitting portion 12 shall be 1 μm or less and a conical angle α shall be 30 to 90 degrees. Desirably, a diameter of the columnar portion 11 shall be 300 μm or less and 20 or more of the columnar members contact with the light-emitting portion 12. Moreover, desirably, a refractive index ratio n2/n1 between a refractive index n1 of the columnar portion and a refractive index n2 of the light-emitting portion shall be 1 or more. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light emitting structure and a light emitting element having improved luminance by efficiently extracting light to the outside.

  As a flat panel display (FPD) using fine particles and a thin film having a light emitting function, an electroluminescence (EL) display, a field emission display (FED), and the like are attracting attention. EL displays are self-luminous, and are completely solid, so they have excellent environmental resistance.

EL devices include inorganic EL using electroluminescence in inorganic materials and organic EL using current injection light emission in organic materials. In general, in these EL elements, light incident on the interface at an angle greater than the critical angle out of the light generated inside the element is totally reflected, so that it is difficult to extract all the light to the outside. . The light extraction efficiency depends on the material constituting the element, but is generally about 20%. As a method for improving the light extraction efficiency, for example, a method of providing a low refractive index layer between the transparent electrode layer and the transparent substrate (Patent Document 1), a method of making the transparent electrode an uneven structure (Patent Document 2), etc. are proposed. Has been.
JP 2002-278477 A JP 2004-296438 A

  However, if the low refractive index layer and the light scattering layer are provided in addition to the necessary components such as the substrate and the light emitting layer as in the above method, the element structure becomes complicated, the manufacturing process becomes complicated, and the quality of the light emitting element is increased. Management becomes difficult. In addition, the manufacturing cost increases.

  In general, when a single crystal thin film is used for the light emitting portion (FIG. 9A), the quantum efficiency is excellent, but the light extraction efficiency is limited to about 20%. Moreover, since it is difficult to produce a single crystal having a large size, the cost becomes high.

  On the other hand, in the conventional configuration using microcrystals or fine particles in the light emitting part (FIG. 9B), light extraction efficiency increases due to light scattering at the interface. However, at the same time, the non-luminous center at the interface increases due to the increase in surface area, so that the quantum efficiency decreases. Although improvement can be achieved by using microcrystals having a relatively large size (0.1 μm or more), since the surface is generally rough, it becomes an obstacle to the formation of a thin film device. The above problems can be solved by the following configuration and manufacturing method of the present invention.

  With such a technical background, the present invention relates to a light emitting structure having a structure in which the light emitting layer itself improves the light extraction efficiency, and a method for manufacturing the same.

The light emitting structure of the present invention has a light emitting layer provided on a base surface, and the light emitting layer includes a plurality of light emitting parts and a plurality of columnar parts provided between the plurality of light emitting parts. A structure,
The light emitting portion has a cross-sectional area in a direction parallel to the ground surface, from the ground surface side toward the surface opposite to the ground surface side, or from the surface side opposite to the ground surface side to the ground surface side. A three-dimensional shape that decreases toward the
The plurality of columnar portions extend in a direction substantially perpendicular to the base surface,
At least a part of the plurality of columnar portions is in contact with the light emitting portion, and light emitted from the light emitting portion is extracted through the columnar portion.

  The light emitting part is preferably a cone. The pyramid includes a cone, a triangular pyramid, a quadrangular pyramid, a pyramid of five or more pyramids, a truncated cone, a triangular frustum, a quadrangular pyramid, and a pyramid of five or more pyramids. Here, in the present application, the term “substantially perpendicular” means to include the degree of being perpendicular to the direction perpendicular to the substrate but being substantially perpendicular (the same applies hereinafter). In order for the generated light to be efficiently extracted from the columnar site, it is preferable to be in contact with 20 or more columnar sites.

  Here, the light emitting layer is preferably a thin film having a thickness of 5 μm or less. Here, it is assumed that the light-emitting portion has a conical shape, a regular triangular pyramid, or a regular pyramid shape that is greater than or equal to a regular pyramid shape (or a truncated cone shape, regular triangular pyramid shape, or a regular pyramid shape that is greater than or equal to a regular pyramid shape). . At that time, the shape of the cross section in the direction parallel to the base surface in the light emitting part is such that the diameter of the circle, the length of one side of the regular triangle, or the length of the diagonal line of the square shape of the regular square or more is 1 μm or less. It is desirable. Further, it is assumed that the columnar part has a conical shape, a regular triangular pyramid, or a regular pyramid shape greater than or equal to a regular pyramid shape (or a truncated cone shape, a regular triangular pyramid shape, or a regular pyramid shape that is greater than or equal to a regular pyramid shape). In that case, the shape of the cross section in the direction parallel to the base surface in the columnar part is that the diameter of the circle, the length of one side of the equilateral triangle, or the length of the diagonal line of the equilateral shape of the equilateral square or more is 300 nm or less. It is desirable to be.

  In addition, the light emitting part cannot be regarded as a conical shape, a regular triangular pyramid shape, or a regular pyramid shape having a regular pyramid shape or more (or a truncated cone shape, a regular triangular pyramid shape, or a regular pyramid shape having a regular pyramid shape or more). In some cases. In that case, when the cross-sectional size in the direction parallel to the base surface in the light emitting portion is converted into a circle having the same cross-sectional area, the diameter of the circle is preferably 1 μm or less. In some cases, the columnar part cannot be regarded as a conical shape, a regular triangular pyramid shape, or a regular pyramid shape that is greater than or equal to a regular pyramid shape (or a truncated cone shape, regular triangular pyramid shape, or a regular pyramid shape that is greater than or equal to a regular pyramid shape). is there. In that case, when the size of the cross section in the direction parallel to the base surface in the columnar portion is converted into a circle having the same cross-sectional area, the diameter of the circle is preferably 300 nm or less. Further, the refractive index ratio n2 / n1 between the refractive index n1 of the columnar part and the refractive index n2 of the light emitting part is preferably 1 or more so that light is effectively extracted from the light emitting part to the columnar part.

Moreover, it is preferable that the chemical formulas of the materials of the light emitting part and the columnar part are both ZnWO ₄ , the crystal structure of the light emitting part is monoclinic, and the crystal structure of the columnar part is triclinic.

Furthermore, the light emitting material is preferably a light emitting material that is an oxide, such as tungsten composite oxide containing tungsten oxide or zinc oxide. In addition, as another example of the light emitting material, an organic substance can be used as a light emitting portion, and examples thereof include organic light emitting materials such as FIrpic and Ir (ppy) ₃ .

  The present invention also provides a light emitting element using the above light emitting material. In particular, an inorganic EL element, an organic EL element, an organic / inorganic composite light emitting element, a fluorescent thin film for FED, and a scintillator for radiation are provided.

  The present invention also provides a method for producing the light emitting material. In other words, this is a film forming method in which a light emitting layer composed of a cone-shaped light emitting portion and a columnar portion in contact therewith is simultaneously formed on a substrate by sputtering.

  According to the present invention, a light emitting structure, particularly a fluorescent film, with improved light extraction efficiency, high quantum efficiency and improved luminance can be obtained. The light emitting structure can be used for inorganic EL or organic EL phosphor films.

Hereinafter, the light emitting material according to the embodiment of the present invention will be described. 1 and 2 schematically show an example of a light emitting structure according to the present invention, particularly a thin film light emitting structure.
FIG. 1A is a plan view of a thin film when the light emitting site of the present invention is conical and the columnar site serving as a light scattering site is cylindrical, and FIG. 1B is a cross-sectional view thereof. Reference numeral 11 denotes a cylindrical columnar part, and 12 denotes a conical light emitting part. External light extraction efficiency is improved by extracting light generated in the light emitting region 12 to the outside through the columnar region 11. The optimum size and shape of the light emitting portion 12 depends on the type of the light emitting portion and the applied element configuration, but it is preferable that the diameter of the cone bottom is 1 μm or less and the cone angle α is 30 to 90 degrees. Further, the diameter of the columnar portion 11 is preferably 300 nm or less, and it is preferable that 20 or more columnar portions 11 are in contact with the light emitting portion 12. This is because when the number of contact with the columnar portions 11 is less than 20, the amount of light extracted through the columnar portions 11 is reduced. In addition, when the cone angle α is smaller than 30 degrees, the amount of light extracted through the columnar part 11 decreases, and when it exceeds 90 degrees, the area of the columnar part in contact with the plurality of light emitting parts decreases and the light is extracted through the columnar part 11. Less light. By adopting the configuration as shown in FIG. 1, it is possible to achieve both high quantum efficiency and high light extraction efficiency at the light emitting site. Thereby, a fluorescent thin film with high luminous efficiency is obtained.

  FIG. 2A is a plan view of a thin film when the light emitting site of the present invention is a hexagonal pyramid and the columnar site that is a columnar site is a hexagonal column, and FIG. 2B is a cross-sectional view thereof. Reference numeral 21 denotes a hexagonal columnar portion, and 22 denotes a hexagonal pyramidal light emitting portion. External light extraction efficiency is improved by extracting light generated in the light emitting region 22 to the outside through the columnar region 21. The optimum size and shape of the light emitting portion 22 depends on the type of light emitting portion and the applied element configuration, but it is preferable that the diagonal line of the hexagonal pyramid base is 1 μm or less and the cone angle α is 30-90 degrees. It is preferable that the diagonal line of the columnar part 21 is 300 nm or less, and 20 or more columnar parts are in contact with the light emitting part 22.

FIG. 3 shows a configuration example in the case where the light emitting structure of the present embodiment is used as an inorganic EL element, and is a conceptual diagram of an AC driven inorganic EL element that takes out light from the substrate side. 31 is an electrode layer, 32 is a dielectric layer, 33 is a light emitting part, 34 is a columnar part that is a light scattering part, 35 is a transparent electrode, 36 is a substrate, and 37 is a fluorescent thin film layer made of a light emitting structure according to this embodiment. It is. One of the dielectric layers 32 becomes a base surface. A dielectric thin film such as BaTiO ₃ is effective as the dielectric layer 32 used in the AC drive type, and the film thickness is preferably in the range of 10 nm to 100 μm. When extracting light from the substrate side, use a transparent electrode having conductivity such as In ₂ O ₃ or SnO ₂ , ZnO, ITO doped as the transparent electrode 35 so that the generated light is transmitted, 36 is preferably transparent glass or plastic. As the electrode layer 31, various metals such as Au, Pt, and Ag, alloys, and a transparent conductive film can be used. Here, the area where each light emitting portion 33 is in contact with the dielectric layer 32 on the back electrode 31 side is at most 1 μm ^2, which is an extremely small area compared to the area where the back electrode 31 is in contact with the dielectric layer. For this reason, this light-emitting element has a feature that the surface has excellent surface flatness due to the above-described configuration even though the fluorescent layer has a light-emitting portion made of a relatively large (several μm) crystal. . Therefore, the thin film of this invention is excellent in the application to the fluorescent layer of a thin film device.

  In the embodiment described above, the evaluation of the size of the bottom portion of the light emitting portion and the size of the cross section of the columnar portion is a circle or a hexagon, and thus is a diameter or a diagonal length. However, the cross-sectional shape of the bottom part of the light emitting part and the columnar part is not particularly limited, and may be various shapes, for example, a hexagonal shape that is broken. Therefore, the evaluation of the size of the bottom of the light emitting part and the size of the cross section of the columnar part is described in a predetermined shape (here, a hexagonal shape, as shown in FIG. 17, but the actual shape varies). The diameter d was calculated by converting it into a circular shape, and the diameter of the circle was used as the evaluation value of the size. According to this evaluation method, various shapes can be converted into a circle and evaluated.

  The light emitting structure of the present invention is shown in FIG. There is a transparent substrate 100 serving as a lower ground (an electrode or the like is formed on the substrate if necessary, but in this case, the surface of the electrode or the like serves as a base surface). There is a configuration in which a light emitting layer including a light emitting portion 101 and a columnar portion 102 is provided on a substrate, and light is extracted from the transparent substrate 100 side. In this case, light can be extracted from both sides of the light emitting layer. In addition, as shown in FIG. 11, a light emitting layer including a light emitting portion 101 and a columnar portion 102 is provided on an opaque substrate 100 (which may be a transparent substrate, and an electrode or the like is formed if necessary) 100. There is a configuration in which light is extracted from a surface opposite to the substrate 100 side of the light emitting layer.

  Further, as shown in FIG. 12, the light emitting part may have a shape (conical shape having a step on the side surface) in which discs, hexagonal plates, and the like are stacked so as to reduce the area. With such a shape, the area of the side surface of the light emitting part is increased, and the light emission efficiency can be further increased. Here, an example in which six layers are stacked is shown, but the number of steps is set as necessary. As shown in FIG. 13, the apex of the cone of the light emitting part 101 does not have to be in contact with the substrate. As shown in FIG. 14, the light emitting part has a trapezoidal shape such as a truncated cone or a hexagonal frustum. May be.

  Furthermore, as shown in FIG. 15, the bottoms of the light emitting sites may be in contact with each other. When the light emitting part has a regular pyramid shape such as a regular hexagonal pyramid, the bottom part of the light emitting part may be arranged so as to contact each other without a gap. In this case, since the light emitting parts are arranged without a gap, the light emission efficiency can be further increased.

  In addition, as shown in FIG. 16, the light emitting portion 301 may have a triangular prism shape with a triangular cross section (the cross section may have a trapezoidal shape), and the side surface of the triangular prism may be in contact with the substrate. . In FIG. 16, the columnar portion is omitted.

  Hereinafter, the present invention will be described with reference to examples.

[Example 1]
By sputtering in this embodiment will be described with reference to FIG. 4 for an example the chemical formula of the emission sites and the columnar portion is ZnWO ₄ together. In this example, a thin-film phosphor having a light emitting portion having a monoclinic crystal structure and an inverted conical shape from the substrate to the film surface and a columnar portion having a crystal structure of triclinic system and a diameter of about 100 nm was prepared. . 4A and 4B are schematic views of the thin film phosphor prepared in this example. FIG. 4A is a schematic view of a planar structure, and FIG. 4B is a schematic view of a cross-sectional structure. It created by the process shown below.

A fluorescent thin film having a thickness of 700 nm was formed on the silicon substrate 1 having a substrate temperature of 600 ° C. by RF sputtering and simultaneously sputtered with ZnO and WO ₃ as targets. FIG. 5 shows the substrate-target arrangement during film formation. A ZnO target having a diameter of 2 inches (inches) and a WO ₃ target were used as targets, and a 4 inch silicon substrate was used as the substrate. The incident direction of the two targets is shifted by 120 degrees, tilted by 20 degrees with respect to the vertical direction of the board, and the intersection is shifted upward from the center of the board, the output is set to 150 W and 150 W, respectively, for 40 minutes Film formation was performed. When the prepared film was irradiated with ultraviolet rays having a wavelength of 254 nm, pale blue light emission was observed.

The planar structure and the cross-sectional structure of the region having the strongest fluorescence intensity were observed with a transmission electron microscope. Then, as shown in FIG. 4, the columnar portion 41 that is a light scattering portion having a structure in which columnar crystal portions of about 100 nm are gathered, and the diameter of the bottom of the cone portion on the film surface grows in an inverted cone shape from the silicon substrate. It was composed of a light emitting portion 42 having a large crystal structure of about 1 μm. When the composition analysis was performed by TEM-EDS, the columnar part 41 and the light emitting part 42 had almost the same composition. Further, from the analysis by X-ray diffraction and electron diffraction, the columnar portion 41 has a triclinic ZnWO ₄ structure, and the inverted conical light-emitting portion 42 made of a large crystal has a monoclinic ZnWO ₄ structure. . As a result, a fluorescent thin film composed of a light emitting portion and a columnar portion having the same composition but different only in the crystal structure was prepared. When the cone angle α of the light emitting part 42 was 90 degrees, the light emitting part 42 was in contact with about 30 columnar parts 41.

  FIG. 6 shows the results of cathodoluminescence measurement in a TEM by 80 keV electron beam irradiation. The light emission 52 from the light emitting part showed strong light emission from 400 to 600 nm because the light extracted from the columnar part as the light scattering part was added in addition to the emission from the light emitting part. On the other hand, light emission 51 from the columnar part was weak from the columnar part itself, and the light emission intensity was about 1/6 times that of light emission 52 from the light emission part. In addition, the strongest light emission was observed in the region where the cone angle α of the light emitting portion 42 was about 90 degrees. It is considered that the number of light emitting portions 42 contacting the columnar portion 41 increases as the cone angle α increases, so that light extraction can be performed efficiently. On the other hand, if α increases too much (α> 90 degrees), the ratio of total reflection of the generated light at the interface between the light emitting portion 42 and the columnar portion 41 increases. The extraction efficiency is considered to be optimal. In the device structure as described above, since the light emitting site is large, the loss due to non-radiative recombination at the interface is small compared to the case of using a microcrystal, and the quantum efficiency is excellent. The light is effectively extracted from 42. Therefore, a highly efficient light emitting element was able to be created.

[Example 2]
In this example, an example of manufacturing a light emitting element using an inorganic light emitting material in a light emitting portion is shown. 7A to 7L are cross-sectional views for each process of this example. This will be described in the order of steps.

  (a) An ITO film 70 is formed on the transparent substrate 71, and (b) resin A (refractive index 1.6) 72 is applied by 1 μm.

  (c) (d) A pattern is formed by pressing with a mold 73 (columnar convex structure having a diameter of 100 nm, a pitch of 200 nm, and a height of 1 μm), and (e) resin B (refractive index 1.3) 74 is applied to the pattern. Embed. This resin B constitutes a columnar part.

  (f) A negative photoresist 76 is applied, (g) (h) exposure and development are performed using the pattern mask 75, and etching is performed so that the taper angle is 90 degrees. Here, by arbitrarily selecting the shape of the pattern mask 75, the shape of the light emitting portion can be freely changed. For example, if the pattern mask 75 is circular, it has a conical shape, if it is polygonal, it has a polygonal pyramid shape.

  By selecting the photoresist 76 that has a higher etching rate than the resins A and B, the photoresist 76 is etched faster when the resins A and B are etched. Therefore, the resins A and B are tapered. Is etched. The taper angle can be arbitrarily controlled by controlling the etching rate ratio between the resins A and B and the photoresist.

  (i) Phosphor 77 is embedded in the tapered portion by CVD, sol-gel, sputtering, or the like (for example, ZnS), and (j) the remaining photoresist is removed. (k) After the dielectric thick film 78 is formed, (l) the electrode 79 is formed to produce a target element.

In the light-emitting element manufactured by the above method, light generated in the light-emitting portion is extracted to the columnar portion. And it repeats total reflection at the columnar part, and is incident at an angle close to perpendicular to the light extraction surface, so that total reflection is suppressed, and is about 1.5 times that of a light emitting device with a uniform light emitting film that does not have a columnar part that becomes a light scattering part. The external luminous efficiency can be obtained.
[Example 3]
In this example, an example of manufacturing a light-emitting element using an organic light-emitting material in a light-emitting portion in the same process as in Example 2 will be described. FIGS. 8A to 8K are cross-sectional views for each process of this example. This will be described in the order of steps.

  (a) An ITO film 80 is formed on the transparent substrate 81, and (b) resin A (refractive index 1.6) 82 is applied by 1 μm.

  (c) (d) A pattern is formed by pressing with a mold 83 (columnar convex structure having a diameter of 100 nm, a pitch of 200 nm, and a height of 1 μm), and (e) resin B (refractive index 1.3) 84 is applied to the pattern. Embed. This resin B constitutes a columnar part.

  (f) A negative photoresist 86 is applied, (g) (h) exposure and development are performed using the pattern mask 85, and etching is performed so that the taper angle is 90 degrees. Here, by arbitrarily selecting the shape of the pattern mask 85, the shape of the light emitting portion can be freely changed. For example, if the pattern mask 75 is circular, it has a conical shape, if it is polygonal, it has a polygonal pyramid shape.

  By selecting a photoresist 86 that has a faster etching rate compared to resins A and B, the photoresist 86 is etched faster than that when the resins A and B are etched, so the resins A and B are tapered. Is etched. The taper angle can be arbitrarily controlled by controlling the etching rate ratio between the resins A and B and the photoresist.

  (i) Using a vacuum deposition apparatus, deposit 300 TPD to form a hole transport layer, and subsequently form 500 q of Alq on the TPD film as an organic material light emitting layer 87 to form an electron transport layer and light emitting layer. (J) The remaining photoresist is removed. (k) Al is formed as the back electrode 88 to produce a desired element.

  In the light-emitting element manufactured by the above method, light generated in the light-emitting portion is extracted to the columnar portion. Then, total reflection is repeated at the columnar portion and incident at an angle close to perpendicular to the light extraction surface, so that total reflection is suppressed. As a result, an external light emission efficiency of about 1.2 times that of a light-emitting element using a uniform light-emitting film that does not have a columnar portion serving as a light scattering portion can be obtained.

  The present invention can be used as a light emitting layer of a display device such as an electroluminescence (EL) display or a field emission display (FED) as a flat panel display (FPD).

It is the schematic when the light emission site | part of a light emitting structure of embodiment of this invention is a cone and a columnar site | part is a cylinder. It is the schematic when the light emission site | part of the light emission structure of embodiment of this invention is a polygonal pyramid, and a columnar site | part is a polygonal column. It is a block diagram of the light emitting element by this invention. 1 is a configuration diagram of a light emitting material created in Example 1. FIG. 1 is a schematic view showing a film forming method of Example 1. FIG. 3 is a result of cathodoluminescence measurement of Example 1. It is a block diagram of the light emitting element using an inorganic luminescent material. It is a block diagram of the light emitting element using an organic luminescent material. It is a conventional block diagram. It is a figure which shows the structural example of the light emitting structure of other embodiment of this invention. It is a figure which shows the structural example of the light emitting structure of other embodiment of this invention. It is a figure which shows the structural example of the light emitting structure of other embodiment of this invention. It is a figure which shows the structural example of the light emitting structure of other embodiment of this invention. It is a figure which shows the structural example of the light emitting structure of other embodiment of this invention. It is a figure which shows the structural example of the light emitting structure of other embodiment of this invention. It is a figure which shows the structural example of the light emitting structure of other embodiment of this invention. It is a figure which shows the method of the magnitude | size evaluation of a light emission site | part or a columnar site | part.

Explanation of symbols

11, 21, 34, 41 Columnar part (light scattering part)
12, 22, 33, 42 Luminescent site
31 electrodes
32 Dielectric layer
35 Transparent electrode
36 PCB
37 Fluorescent thin film layer
61 Light emission from columnar part
62 Light emission from light emitting part
70 ITO
71 Transparent substrate
72 Resin A
73 Mold
74 Resin B
75 Pattern mask
76 photoresist
77 phosphor
78 Dielectric thick film
79 electrodes
80 ITO
81 Transparent substrate
82 Resin A
83 Mold
84 Resin B
85 Pattern mask
86 photoresist
87 Organic material light emitting layer
88 electrodes
91 electrodes
92 Insulation layer
93 Dielectric film
94 Light-emitting layer
95 Transparent electrode
96 glass substrate

Claims (15)

A light-emitting structure having a light-emitting layer provided on a lower ground, the light-emitting layer including a plurality of light-emitting portions and a plurality of columnar portions provided between the plurality of light-emitting portions,
The light emitting portion has a cross-sectional area in a direction parallel to the ground surface, from the ground surface side toward the surface opposite to the ground surface side, or from the surface side opposite to the ground surface side to the ground surface side. A three-dimensional shape that decreases toward the
At least a part of the plurality of columnar portions is in contact with the light emitting portion, and light generated at the light emitting portion is extracted through the columnar portion.   The light emitting structure according to claim 1, wherein the plurality of columnar portions extend in a direction substantially perpendicular to the base surface.   3. The light emitting structure according to claim 1, wherein the light emitting part is a cone.   The light emitting structure according to any one of claims 1 to 3, wherein the light emitting part is in contact with 20 or more columnar parts.   5. The light emitting structure according to claim 1, wherein the light emitting layer has a thickness of 5 μm or less. 6. The light emitting structure according to claim 1, wherein a cross-sectional shape of the light emitting portion in a direction parallel to the base surface is a circular shape, a regular triangle, or a regular square shape that is equal to or more than a regular square. And the diameter of the circle, the length of one side of the regular triangle, or the length of the diagonal line of the regular shape of the regular square or more is 1 μm or less,
The shape of the cross section in the direction parallel to the base surface in the columnar part is a circle, a regular triangle, or a regular square shape that is equal to or greater than a regular square, and the diameter of the circle, the length of one side of the regular triangle, or a regular square A light-emitting structure having a diagonal length of 300 nm or less.   The light emitting structure according to any one of claims 1 to 5, wherein the size of a cross section in a direction parallel to the base surface in the light emitting portion is converted into a circle having an equal cross sectional area, A light emitting structure in which the diameter of a circle is 1 μm or less, and the size of a cross section in a direction parallel to the base surface in a columnar part is a circle having a diameter of 300 nm or less when converted to a circle having the same cross-sectional area body.   The light emitting structure according to any one of claims 3 to 7, wherein a cone angle of the cone is in a range of 30 degrees to 90 degrees.   The light emitting structure according to any one of claims 1 to 8, wherein a refractive index ratio n2 / n1 between a refractive index n1 of the columnar part and a refractive index n2 of the light emitting part is n2 / n1> 1. Luminescent structure. In the light-emitting structure according to any one of claims 1 8, the light emitting structure formula of the emission portion and the columnar portion of the material is ZnWO ₄ together.   The light emitting structure according to claim 10, wherein a crystal structure of the light emitting portion is a monoclinic crystal.   12. The light emitting structure according to claim 10, wherein the columnar portion has a triclinic crystal structure. In the method of forming a film consisting of a cone-shaped light emitting part and a columnar part in contact with it on a substrate,
Arranging the substrate and the plurality of targets such that a first axis substantially perpendicular to the substrate surface and a second axis substantially perpendicular to the target surface intersect;
Forming a film containing the plurality of target materials on the substrate.   14. The method for producing a film containing triclinic crystal according to claim 13, wherein an angle formed by the first axis and the second axis is approximately 20 degrees. Provided with a light emitting layer having a light emitting portion and a light scattering portion on a substrate,
The light scattering portion includes a plurality of columnar parts; and
In the cross section of the said light emitting layer in a position perpendicular | vertical to the said substrate surface, the shape of the said light emission site | part is a triangle or a trapezoid, The light emitting structure characterized by the above-mentioned.